title: Impaired ability of patients with familial isolated vitamin E deficiency to incorporate alpha-tocopherol into lipoproteins secreted by the liver.
abstract: Plasma and lipoprotein alpha-tocopherol concentrations of four patients with familial isolated vitamin E deficiency and six control subjects were observed for 4 d after an oral dose (approximately 15 mg) of RRR-alpha-tocopheryl acetate labeled with six deuterium atoms (d6-tocopherol). Chylomicron d6-tocopherol concentrations were similar in the two groups. d6-Tocopherol concentrations of plasma, very low (VLDL), low (LDL), and high (HDL) density lipoproteins were similar in the two groups only during the first 12 h; then these were significantly lower, and the rate of disappearance faster, in the patients. The times (tmax) of the maximum chylomicron d6-tocopherol concentrations were similar for the two groups, but tmax values in the controls increased in the order: chylomicrons less than VLDL less than or equal to LDL approximately HDL, while the corresponding values in the patients were similar to the chylomicron tmax. Thus, plasma d6-tocopherol in controls increased during chylomicron and VLDL catabolism, whereas in patients it increased only during chylomicron catabolism, thereby resulting in a premature and faster decline in the plasma tocopherol concentration due to a lack of d6-tocopherol secretion from the liver. We suggest that these patients are lacking or have a defective liver "tocopherol binding protein" that incorporates alpha-tocopherol into nascent VLDL.
authors.affiliation: Department of Medicine, New York University School of Medicine, New York 10016.
authors.forename: M G
authors.initials: MG
authors.lastname: Traber
authors.forename: R J
authors.initials: RJ
authors.lastname: Sokol
authors.forename: G W
authors.initials: GW
authors.lastname: Burton
authors.forename: K U
authors.initials: KU
authors.lastname: Ingold
authors.forename: A M
authors.initials: AM
authors.lastname: Papas
authors.forename: J E
authors.initials: JE
authors.lastname: Huffaker
authors.forename: H J
authors.initials: HJ
authors.lastname: Kayden
mesh_terms: D000042:Absorption; D000328:Adult; D002914:Chylomicrons / Q000096:biosynthesis; D005260:Female; D006801:Humans; D008074:Lipoproteins / Q000096:biosynthesis*; D008099:Liver / Q000378:metabolism*; D008297:Male; D014810:Vitamin E / Q000378:metabolism*; D014811:Vitamin E Deficiency / Q000378:metabolism*
chemical_list: D002914:Chylomicrons; D008074:Lipoproteins; D014810:Vitamin E